The present invention relates to a display method and apparatus for producing an image in the field of view of a person wherein the viewed image represents the written equivalent of the spoken dialogue, for example, in a film in a cinema or accompanying a live performance in a theater.
A problem facing deaf or hard of hearing people is that reading of written material accompanying a performance is not efficient unless the field of view of the display is equivalent to the field of view of the performance watched. Furthermore, the field of view of the display must be sufficiently large to show at least one line containing several words. Reading efficiency for deaf or hard of hearing people improves if two or three such lines are provided by the display. Reading efficiency is important because it is essential that the user of the display be able to read fast enough to easily keep up with the dialogue of the film or the live performance, while at the same time view the performance, and thereby suitably enjoy the experience.
Many situations exist in which it is desirable to present information to an individual by superimposing an image onto her/his normal field of vision. In addition to the so-called heads up displays now used in many aircraft, three patents describe basic techniques for wearable displays which superimpose an image with the intent of improving lipreading of speech information. Two patents to Upton U.S. Pat. Nos. 3,463,885 ('885) and 3,936,605 ('605) disclose a display which is mounted upon a pair of spectacles intended to be worn by a deaf or hard of hearing person. In Upton ('885), entitled SPEECH AND SOUND DISPLAY SYSTEM, a number of miniature light bulbs are mounted on a lens of the spectacles, and each bulb is associated with a class of speech sounds. A bulb is activated in response to the detection of a speech sound in a given class. In one embodiment, a single bulb is activated in response to the detection of a given class. In another embodiment, sounds which represent combinations of sound classes activate more than one bulb, and in a third embodiment, separate bulbs are activated to denote combinations.
In Upton ('605), entitled EYEGLASS MOUNTED VISUAL DISPLAY, a device is described wherein the source of the image is a light emitting diode (LED) mounted on the eyeglass frame at the side of the eye of the wearer and out of his normal field of view. A small, generally spherical mirror is mounted on the eyeglass lens and is of appropriate focal length to project a virtual, in-focus image into the field of view of the wearer.
Another patent, McCartney, U.S. Pat. No. 4,414,431, entitled METHOD AND APPARATUS FOR DISPLAYING SPEECH INFORMATION, describes an alternate method for displaying speech information as an aid to lipreading. In McCartney, a wearable heads up display with a large aperture spherical mirror is used as a magnifier for a light emitting diode display and as a beam combined to superimpose the magnified image on the normal field of view of the wearer. A magnified virtual image of visual symbols representing speech information is produced approximately one meter away from the viewer and can be centered about the speaker's face to allow simultaneous viewing of the speaker's lips and the symbols. The display achieves high symbol brightness while consuming little electrical power by using a large spherical mirror made from glass with a high index of refraction. The ability to place small LED multisegment displays close to the eye-mirror optical axis results in an optical system which both is simple and does not interfere significantly with normal vision.
In Baker et al., U.S. Pat. No. 4,456,793, there is disclosed an infrared telecommunications system in which a building is equipped with infrared transceivers. In similar arrangement, a theater, movie house, stadium, or other location of a performance may be equipped with suitably mounted transmission apparatus for infrared transmission to a pair of infrared receiving glasses worn by a deaf or hard of hearing person.